KR102156455B1 - Thrust washer - Google Patents

Abstract

A thrust washer for a sliding bearing, comprising a substrate of a thrust washer having an axial surface, and a polymer layer having a thickness on the axial surface of the substrate, wherein the polymer layer has at least one oil distribution groove. It features.

Description

THRUST WASHER

The present invention relates to a thrust washer comprising an axial surface having oil distribution grooves, in particular to a thrust washer used in vehicle engines, transmissions, pumps and compressor systems.

In an internal combustion engine, the bearing assemblies each typically include a pair of half bearings that hold a crankshaft that can rotate around an axis. At least one partial bearing comprises a hollow bearing shell having a wholly cylindrical shape, the bearing shell having a thrust washer extending outwardly (radial direction) at each axial end and having a wholly semicircular shape. In some partial bearings a single structure of bearing shell and thrust washers is used, while in other partial bearings the bearing shell and thrust washers are mechanically loosely connected to features such as clips, and in other types of partial bearings Thrust washers are permanently assembled on the bearing shell by deformation of the connecting feature. In other bearing assemblies, it is known to use circular or annular thrust washers.

Once the engine is started, lubricating oil is provided between the axial journal portion of the crankshaft and the bearing shell and is provided between the thrust washer and the corresponding surface of the associated webs of the crankshaft extending perpendicular to the rotational axis of the crankshaft. do. However, when the engine is started, the pressure of the oil is low and if the shaft comes into contact with the bearing shell or thrust washer, it may provide inappropriate lubrication. In addition, even when the oil is supplied at a normal operating pressure, the shaft can be brought into contact with the thrust washer due to an axial load on the shaft (when gear shifting is performed or by design of some automatic transmissions). Thus, the thrust washer and the bearing shell have a moving surface capable of withstanding the sudden contact. Known bi-metal thrust washers comprise a steel backing (substrate) with a moving layer of aluminum tin (or copper base alloy) on the axial side of the substrate, and machining the profile into the moving layer. Oil distribution grooves are provided by embossing to provide a profile by either or by modifying the aluminum-tin moving layer.

The fuel saving operation plan is used in vehicle engines to increase the frequency with which the engine is started. According to the "Stop-Start" operation plan, the vehicle motion is stopped and restarted, the engine is also stopped and restarted. According to the "hybrid" operating scheme, the engine is turned off when the vehicle is powered by an alternative power source and is often powered by electric power. When the frequency at which the engine is started increases according to the operation plan, the frequency of contacting the journal of the crankshaft and the corresponding surface of the web with the thrust washer and the bearing shell, respectively, and as a result, the wear of the moving surface increases. And the demands on the performance of the bearing shell are increased.

The oil distribution grooves extend outwardly across the axial movement surface and extend radially from the inner edge to the outer edge, for example. The oil distribution groove may comprise a deep channel, the channel having a gentle sloping ramp on each side between the channel and the pad area. The inclined region provides a tapered spacing between the thrust washer and the counter face of the crankshaft web, causing the lubricant to flow from the groove across the axial face of the thrust washer and hydrodynamic wedge of the lubricating oil. wedge) to easily maintain the separation state between the thrust washer and the corresponding surface of the web. Known oil distribution grooves are machined (eg milled) into a moving layer or formed by an embossing process. However, manufacturing tolerances in the process of cost-effectively machining or embossing the depth of the groove, particularly for all inclined regions, are important and increase the complexity of the manufacturing process.

Known bimetallic washers are manufactured by stamping blanks from a bimetallic sheet, and the manufacturing process generates bimetallic waste. Similarly, the washers further generate bimetallic waste after the end of their life. However, since it is difficult to separate the metals (i.e., separate the steel rear portion from the moving layer), it is difficult to recycle the bimetallic waste.

According to a first feature of the present invention, as a thrust washer for a sliding bearing, a thrust washer comprising a substrate of a thrust washer having an axial surface and a polymer layer having a thickness on the axial surface of the substrate is provided, and the polymer The layer has at least one oil distribution groove.

A second feature of the invention comprises a flange bearing comprising a thrust washer according to the first feature, wherein the thrust washer is provided at the axial end of the bearing shell. The flange bearings (i.e. one or two thrust washers and bearing shell) may be assembled to be detachable from each other, loosely clipped and physically inseparably connected or may comprise a single part structure. .

A third aspect of the present invention provides a method of manufacturing a thrust washer according to the first aspect of the present invention, the method comprising forming a polymer layer on the axial side of the substrate and curing the polymer layer do.

It is advantageous that the polymer layer can have a greater resilience to wear than the metallic moving layer of the thrust washers according to the prior art.

Because of the precision in which the polymer layer adheres to the substrate (before or after the substrates are stamped or otherwise molded from a sheet), the thrust washers can be manufactured without generating bimetallic waste. Further, at the end of the service life, the treatment of the metal and polymer bimetal thrust washers is advantageous as it becomes less difficult than the treatment of the prior art bimetal thrust washers.

The oil distribution groove is advantageous because it can be formed more precisely in the polymer layer than bimetal thrust washers.

Particularly, when the polymer layer includes metal particles dispersed through a polymer, the polymer movement layer may have a higher wear resistance than the metal (eg, aluminum-tin) movement layer. In addition, when the polymer layer contains solid lubricating particles dispersed through the polymer, the polymer layer can provide a greater compatibility and a smaller coefficient of friction than the aluminum-tin moving layer.

The manufacturing cost for forming the oil distribution groove in the polymer layer is advantageous because it is less than the manufacturing cost for forming the groove by machining the bimetal thrust washer of the prior art because of the relatively low cost of raw materials.

Attaching the polymer layer simplifies waste disposal by eliminating the generation of bimetallic metal debris generated by machining the moving layer of the prior art bimetal thrust washers.

The thrust washer may have a semicircular shape, a circular shape, or an annular shape as a whole.

The thrust washer may have 1 to 10 oil distribution grooves. A thrust washer including an inner edge with a diameter of less than 70 mm may have 1 to 7 oil distribution grooves. Thrust washers with a diameter of 70 mm or more may have 1 to 10 oil distribution grooves.

The polymer layer may have a maximum thickness of 20 to 100 μm after it is completely cured.

The polymer layer may comprise a plurality of stacked polymer sublayers.

The polymer sub-layers may have different patterns.

The oil distribution groove may extend only through the polymer layer.

The oil distribution groove may extend through the polymer layer, and the polymer layer may include a plurality of discontinuous portions separated by at least one oil distribution groove.

The oil distribution groove may extend into the substrate of the thrust washer.

The oil distribution groove may include a channel and a slope region. The channel region is a portion having the deepest groove in the groove, and the slope region has a small slope slope.

The inclined portion region is provided in the polymer layer, and in the inclined portion region, the thickness of the polymer layer increases as it moves away from the channel. The channel region of the oil distribution groove can be formed in the substrate by a rapid manufacturing process (e.g., machining or embossing), and the inclined region is a relatively low cost process (e.g., multi-layered Attached).

The inclined portion region has an inclined portion inclination in which the increase in the thickness of the polymer is less than 25 μm per 1 mm across the axial plane perpendicular to the oil distribution groove.

The oil distribution groove includes a channel between the first slope region and the second slope region. The first and second sloped regions may have different slopes. The use of different slope inclinations is advantageous because the thrust washers can be optimized for a specific direction of rotation of the crankshaft. The oil distribution groove may include a channel and a sloping region, and a boundary of the channel is formed by a sharply sloped edge on the other side of the sloping region. Optionally, the oil distribution groove may include a channel region between sharply inclined edges of the polymer layer.

The polymer layer may have a pad region having a uniform thickness at a position close to the oil distribution groove.

The polymer layer is polyimide/amide resin, acrylate resin, epoxy resin, fluoropolymer (eg, PTFE), and formaldehyde. It may be a plastic polymer material selected from the group including. The polymer layer is a composite of a plastic polymer matrix and particles distributed through the matrix. The particles may be rigid particles (e.g., ceramic powder, silica and aluminum flakes and/or soft particles (e.g., MoS ₂ and fluorinated polymers such as graphite and PTFE). The polymer has a matrix of polyimide/amide plastic polymer material, through which 5 to 25% volume of metal particles (e.g., metal powder and/or metal flakes) and 1 to 20% volume of fluorinated polymer Is distributed and the polyimide/amide resin excluding the introduced impurities is distributed as the remainder.

The polymer layer may be formed by a process selected from the group including a spraying process and a printing process.

The polymer layer may be formed by attaching a plurality of polymer sub-layers.

Successive polymer sub-layers may have different patterns to form a polymer layer having a non-uniform thickness.

The plurality of polymer sub-layers may include sub-layers having different thicknesses. Using sub-layers having different thicknesses improves the thickness control of the polymer layer.

Embodiments of the present invention are further described below with reference to the accompanying drawings.
1A and 1B are perspective views showing thrust washers according to the invention.
Fig. 2A is a sectional view showing a thrust washer formed by a first manufacturing method according to a first embodiment of the present invention.
2B and 2C are cross-sectional views illustrating thrust washers in different manufacturing steps before and after an extended curing step and formed by a second manufacturing method according to a first embodiment of the present invention.
3A and 3B are cross-sectional views showing thrust washers formed by two different manufacturing methods according to the second embodiment of the present invention.
4A is a cross-sectional view of a thrust washer according to a first embodiment of the present invention.
4B and 4C are cross-sectional views showing an optional thrust washer according to a third embodiment of the present invention.
5A is a cross-sectional view showing a thrust washer according to a fourth embodiment of the present invention.
5B is a cross-sectional view showing a thrust washer according to a fifth embodiment of the present invention.
6 is a cross-sectional view showing a thrust washer according to a sixth embodiment of the present invention.

In the above embodiments, the same elements are indicated by the same reference numerals, and in some cases have an integer multiple of 100 and a symbol (eg, primes). For example, in different figures, 100, 100', 200, 200', 300, 300', 400, 400', 400", 500, 500', 600 are used to indicate thrust washers.

1A shows a thrust washer 100 having a substantially semicircular shape (e.g., the thrust washer may have protruding hooks and tabs and is generally used to connect with other parts of the bearing assembly. It has a tapered shape from a semicircle shape). The axial surface 102 of the thrust washer 100 (i.e., a surface perpendicular to the axis of rotation of the shaft accommodated in the bearing assembly including the thrust washer) is formed between the inner and outer edges of the thrust washer and is parallel. It has oil distribution grooves 104. In use, the lubricating oil is pumped into a bearing clearance between the rotating crankshaft journal and the bearing shell and flows out into another gap between the thrust washers and the counter face of the rotating crankshaft web. When the oil distribution groove 104 is formed in the axial surface 102 of the thrust washer 100, the quality of the oil film between the thrust washer and the shaft is improved.

1B shows an optional structure of oil distribution grooves 104' formed on the axial surface 102' of another thrust washer 100', in which the oil distribution grooves are radially directed on the axial surface. Are arranged as.

2A is a cross-sectional view showing a portion of the thrust washer 200 when viewed in a direction perpendicular to the oil distribution groove 204. The thrust washer 200 includes a metal substrate (eg, a steel rear portion) 206 and a profiled polymer layer 208 on the axial side of the substrate.

The polymeric layer 208 has a profile that provides oil distribution grooves 204 between pad regions of uniform thickness. Each of the oil distribution grooves 204 includes a channel 204A and an adjacent pad area 210 and a slope area 204B between the channels. In the illustrated embodiment, the slope region 204B corresponds to about 1/3° and has a small slope slope (θ) of about 1: 300 to 1: 100, for example, 1:200. .

The polymer layer 208 shown in FIG. 2A is formed by a printing deposition process or a spray deposition process. The maximum thickness of the polymer layer 208 (located in the pad region 210) is 20 to 100 μm when completely cured.

2B shows the corresponding thrust washer 200 before the extended final curing step, the polymer layer 208 ′ is formed by a multi-layered deposition process, and the In the process, the successive polymer sub-layers 212' attached to the substrate 206' are stacked to form the polymer layer 208'. For example, successive layers can be narrowed). The thickness of the polymer layer 208' can be precisely controlled by the multilayer attachment. Between the attachment processes of successive sub-layers 212', each sub-layer is dried to remove the solvent (known as flash curing), and the assembled polymer layer 208 after the final sub-layer is attached. Silver is cured by prolonged heating setting the polymer (eg, cross-linking).

Curing the polymer smoothes the profile of the polymer layer 208', and the polymer includes a leveling agent that further promotes the profile to a smooth state. The thrust washers after hardening are shown in Figure 2C.

2B shows a polymer layer 208 ′ formed by only a small number of polymer sub-layers 212 ′ (eg, sub-layers having a thickness of 1 to 25 μm). However, after each sub-layer is attached, a relatively thin and relatively large number of polymer layers 212 ′ may be used to facilitate evaporation of the solvent. Also, if relatively thin layers are used, the polymer layer can be molded more precisely. For example, each polymer sub-layer 212 may have a thickness of only 2 μm and the thickness of the polymer layer 208' in the slope regions 204A, 204B is (parallel to the substrate 206). ) Can increase by 20 μm to 55 μm over a length of several millimeters.

Suitable processes to which the polymer layer 212' may be attached include spraying, screen printing, and pad printing. In particular, screen printing or pad printing can be used to attach polymer layers having a pattern, for example one or more layers of uniform thickness.

Oil distribution grooves 204 shown in FIG. 2A extend through polymer layer 208 to expose regions 214 of substrate 206. In contrast, the polymer layer 308 can extend across the substrate without breaking, as shown in FIGS. 3A and 3B. In the thrust washers 300 and 300 ′, a barrier made of a polymer material is provided between the substrate 306 and the lubricating oil, so that the corrosive action of the substrates 306 and 306 ′ by the additives in the lubricating oil is prevented. It is advantageous.

In the third embodiment shown in FIG. 4A an oil distribution groove 404 extends through the polymer layer 408 into the substrate 406. In particular, the channel 404A is provided with a recessed structure into the substrate 406, and the inclined portion regions 404B are provided in the polymer layer 408. The structure can be manufactured more easily by machining or embossing the channel 404A in the substrate 406 and profiling the polymer layer 408 to shape the inclined portion regions 404B. The formation portion of the channel 404A has a wider spacing than the formation portion of the inclined portion region 404B, and the formation portion can be formed more quickly by forming the channel in the substrate. Also, forming only the sloped regions 404B in the polymer layer 408 requires a thinner polymer and can be manufactured more quickly and more precisely.

An optional design of a third embodiment formed by a multi-layer attachment process is shown in Fig. 4B. Forming only the sloped regions 404B1', 404B2' in the polymer layer 408' for the multi-layer attachment process requires the process of attaching and curing relatively little polymer layer 412', so a thrust washer ( 400') can be molded more quickly.

In Figs. 2A to 4A, each oil distribution groove has a substantially symmetrical structure and has a channel formed between a pair of slope regions having the same slope slope. However, the thrust washer can be optimized for rotation of the shaft in a specific direction, in which case the slope regions may have different slope slopes (i.e. the oil distribution grooves may have asymmetric cross sections) or the slope regions One of these may be omitted. Thus, FIG. 4B shows a thrust washer 400' including sloped regions 404B1 and 404B2 having different sloped slopes θ1 and θ2.

Similarly, according to the thrust washer 400" shown in Fig. 4C, the oil distribution groove includes only one sloping region 404B", which sloping region is at the other side of the channel 404A". A relatively abrupt inclined edge 416A" with respect to polymer 408" (eg, providing an edge perpendicular to the plane of the thrust washer or greater than 45° relative to the plane of the thrust washer). Have.

2A-4C, each oil distribution groove includes a channel and at least one slope area. As shown in Fig. 5A, the thrust washer 500 includes oil distribution grooves that do not have an inclined area, and the grooves are formed by sharp inclined edges 516A, 516B, respectively (for example, the Provides an edge that is perpendicular to the plane of the thrust washer or has an angle greater than 45° to the plane of the thrust washer) A channel formed through the polymer 508 to a channel 518 formed in a concave structure in the substrate 506 (504A). Optionally, the oil distribution grooves may extend only along the surface of the substrate, such as the grooves of FIG. 2A, or may have a depth less than the maximum thickness of the polymer, such as the grooves 304A of FIG. 3A.

According to the embodiment shown in Fig. 5A, before the polymer sub-layers 512 undergo extended hardening, the sharply inclined edges 516A and 516B are substantially perpendicular to the plane of the thrust washer. When attaching the polymer sub-layers 512 of the same pattern (e.g., it is not necessary to smooth the inclined region of the stepped structure during the curing process), the polymer layer 508 is relatively thick, e.g. 25 μm. It can be attached with up to sub-layers, so it can be attached more quickly with a relatively low manufacturing cost. Figure 5B shows a similar embodiment 500' formed after the sub-layers have gone through an extended hardening process, which is different from the embodiment of Figure 5A and is greater than 45 degrees with respect to the plane of the thrust washer (e.g. , 65°), and has edges 516A' and 516B' that are formed on the polymer layer 508' including the edges of each angle and have sharp slopes.

Sublayers 612A and 612B of the polymer layer may have different thicknesses and physical properties, as shown in FIG. 6. For example, the sub-layer 612B may be formed thicker than the sub-layer 612A adjacent to the substrate from the sub-substrate 606.

In the illustrated embodiments, the metal substrate is a steel substrate. The polymer layer is a composite of a plastic polymer matrix and particles distributed through the matrix. The plastic polymer material is selected from the group including polyimide/amide resin, acrylate resin, epoxy resin, fluoropolymer, and formaldehyde. . In particular, the polymer has a matrix of polyimide/amide plastic polymer material, through the matrix, 5 to 25% volume of metal particles (e.g., metal powder and/or metal flakes) and 1 to 20% volume It may be a composite polyimide/amide based polymer such as a composite in which the fluorinated polymer of is distributed and the polyimide/amide resin excluding the introduced impurities is distributed as the remainder. In addition, the polymer composite contains 12.5% volume of aluminum (Al), 5.7% volume of PTFE particles, 4.8% volume of silane, <0.1% volume of other components, and the remainder (about 77% volume) of polyimide. /Can be an amide.

Although shown in Figs. 1A and 1B with respect to a thrust washer having a generally semicircular shape, the present invention is equally applied to circular or annular thrust washers.

The drawings provided in the specification are schematically illustrated and not to scale.

Throughout the detailed description and claims of the present specification, "comprising" and variations of the term have the meaning of "including but not limited to," wherein the expression refers to another moiety, additive, component, integer, or It is not intended to (do not exclude) the step. Throughout the detailed description and claims of this specification, the singular expressions include the plural unless otherwise required. In particular, as long as indefinite articles are used, the specification should be understood as considering the plural as well as the singular unless otherwise required.

It is understood that a feature, integer, characteristic, compound, chemical component or group described in connection with a particular aspect, embodiment or example of the present invention can be applied to other aspects, examples or examples described herein, unless it is inappropriate. Should be. All features disclosed herein (including all appended claims, abstract and drawings) and/or all steps of a disclosed method or process, if at least some of the features and/or steps are mutually exclusive combinations. It can be combined in any combination. The invention is not limited to the details of the above embodiments. The present invention is a novel combination or novel combination of all steps of a method or process that has been extended or disclosed to any novel features or all novel combinations of features disclosed herein (including all appended claims, abstracts and drawings). It expands to one level.

In connection with this application, attention is given to all documents and documents submitted before or concurrently with this specification and which are open for public investigation with this specification, the contents of which are incorporated herein by reference.

100....thrust washers,
102.... axial face,
104....Oil distribution groove.

Claims (20)

As a thrust washer for sliding bearings,
A substrate of thrust washers with an axial face, and
In the thrust washer comprising a polymer layer having a thickness on the axial side of the substrate,
The polymer layer has at least one oil distribution groove,
The oil distribution groove includes a channel and a slope region,
The polymer layer is a thrust washer, characterized in that it comprises a plurality of polymer sub-layers loaded.
delete The thrust washer of claim 1, wherein the polymer sublayers have different patterns.
The thrust washer according to claim 1, wherein the oil distribution groove extends only through the polymer layer.
The thrust washer according to claim 1 or 3, wherein the oil distribution groove extends through the polymer layer, and the polymer layer comprises a plurality of discontinuous portions separated by at least one oil distribution groove. .
6. The thrust washer according to claim 5, wherein the oil distribution groove extends into the substrate of the thrust washer.
delete The thrust washer according to claim 1, wherein the slope region is provided in the polymer layer, and the thickness of the polymer layer in the slope region increases as the distance from the channel increases.
The thrust washer according to claim 8, wherein the inclined portion region has an inclined portion inclination of less than 25 μm per 1 mm in which an increase in the thickness of the polymer crosses an axial surface perpendicular to the oil distribution groove.
The thrust washer according to claim 1, wherein the oil distribution groove comprises a channel between the first slope region and the second slope region.
The thrust washer according to claim 1, wherein the polymer layer has a pad area having a uniform thickness at a position close to the oil distribution groove.
A flange bearing comprising a thrust washer according to claim 1, wherein the thrust washer is provided at the axial end of the bearing shell.
As a manufacturing method of thrust washers for sliding bearings
A substrate of thrust washers with an axial face, and
A polymer layer on the axial side of the substrate,
The polymer layer providing a thrust washer having at least one oil distribution groove,
Forming a polymer layer on the axial side of the substrate, the polymer layer is formed by a process selected from the group including a spraying process and a printing process, and
In the method comprising the step of curing the polymer layer,
The polymer layer is a method of manufacturing a thrust washer for a sliding bearing, characterized in that formed by attaching a plurality of polymer sub-layers.
delete delete 14. The method of claim 13, wherein the successive polymer sublayers have different patterns to form a polymer layer having a non-uniform thickness.
14. The method of claim 13, wherein the plurality of polymer sublayers includes sublayers having different thicknesses. delete delete delete

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